1. Field of the Invention
The present invention relates in general to a video cassette recorder (VCR), and more particularly to apparatus and method for generating video picture adjustment signals in a VCR, which can simultaneously provide a plurality of video picture adjustment signals, i.e., a signal for automatically discriminating the type of a VCR tape on which a video signal is recorded, a signal for automatically detecting a deteriorated state of the VCR tape, a signal for automatically adjusting sharpness of a video picture, and a signal for automatically adjusting tracking of the video picture.
2. Description of the Prior Art
VCR tapes of the VHS system are typically classified into the normal tape type and the super tape type. The normal and super tapes have a difference therebetween according to frequency bands over which energy levels of luminance signals of video signals recorded respectively thereon are distributed. Namely, as shown in FIG. 1 , the recording energy level of the luminance signal of the video signal recorded on the normal tape is mostly distributed over the frequency band of 3.4 MHz-4.4 MHz and the recording energy level of the luminance signal of the video signal recorded on the super tape is mostly distributed over the frequency band of 5.4 MHz-7 MHz.
It can also be seen from FIG. 1 that both recording energy levels of chrominance signals of the video signals recorded respectively on the super and normal tapes are mostly distributed around a frequency of 629 KHz.
Since the normal and super tapes are used in common as the VCR tapes of the VHS system as mentioned above, video reproduction apparatus for VCRs of the VHS system have recently been provided to process video reproduction with respect to both the two types of VCR tapes. In the conventional VCR of the VHS system, the discrimination between the normal and super tapes is accomplished by a provision of tape sensing means disposed in the VCR mechanism for sensing a sensing hole provided on the super tape. Also, the conventional video reproduction apparatus for the VCR of the VHS system comprises separate circuits for adjusting tracking and sharpness of a video picture, respectively. With the separate circuits, the user must manually operate the tracking and sharpness of the video picture while watching a state of the video picture.
In the conventional VCR of the VHS system, as mentioned above, the discrimination between the types of the VCR tapes is accomplished by the mechanical sensing means. This has the effect of increasing the complexity of the VCR mechanism and thus the manufacturing cost thereof. Also, in the conventional video reproduction apparatus for the VCR of the VHS system, the separate circuits are provided to adjust the tracking and sharpness of the video picture and detect a deteriorated state of the VCR tape, respectively, resulting in increase in the manufacturing cost of the VCR mechanism. Further, since the user must manually operate the tracking and sharpness of the video picture with the separate circuits, inconvenience is caused.